A passenger on a Southwest Airlines flight scribbled a message on his arm to his family saying "I love you all" after the plane nosedived and the pilot announced, "We're going down."

Brent Todd, a sales manager in Tampa, Fla., for a biotech company, was traveling on Southwest Flight 3426 to Raleigh, N.C., on Tuesday afternoon.

"I noticed the plane was starting to rock back and forth," he said in a telephone interview. "They get on the intercom and say, 'There is a situation going on right now. Everybody needs to take emergency measures and possibly prepare for a crash landing.'"

The plane started a rapid descent.

Then, the pilot made an announcement on the intercom, he said.

"He did say at that point, 'We're going down,'" Todd said. "That's when everyone kind of pushed the panic button."

Southwest Airlines said it was a misunderstanding, saying the pilot announced the aircraft was going down to a lower altitude.

Todd said passengers believed they were about to die. Some started clawing at the ceiling for oxygen masks, which never fell.

"You're kind of in a situation where you have no control," he said. "You just have to prepare for what's coming."

Todd, 36, said his thoughts focused on his wife, Stacy; his 5-year-old son, Seth; and 3-year-old daughter, Brynn.

"I grabbed the pen out of my bag, I wrote my goodbyes to my family on my arm and followed the flight attendants' instructions and got ready," he said Thursday.

He said he used his arm because a napkin or piece of paper might have been lost in a crash.

"I thought that was one of the only things that was going to be found," he said. "I wanted to make sure I got some message to them."

It wasn't easy.

"First of all, your hand is shaking because you're scared out of your mind," he said. "I tried as best I could to write."

Todd said the woman next to him also wrote a message to her loved ones. Other passengers tried to send text messages.

"I just wrote, 'I love you all' and listed my kids' names and my wife's name again," he said.

A Southwest Airlines spokesman said the pilot's full announcement was, "We're going down to 10,000 feet," but passengers insist they only heard, "We're going down."

The Dallas-based airline said the pilot was following protocol after learning about a maintenance issue.

"As part of the procedure to resolve the issue, the captain notified the cabin using the public address system that he was going down to a lower altitude just before an unplanned but controlled descent," Southwest spokesman Brad Hawkins said.

The passengers acknowledged it was difficult to hear the pilot because it sounded as if he was speaking through a mask.

"You could tell he was on an oxygen supply," Todd said.

The mechanical problem with the jet was resolved, and the plane, which had 96 passengers and five crew members, landed without incident.

Todd said the pilot could have communicated more clearly but added that he and the other passengers are just grateful for the safe landing.

"It was almost a standing ovation," he said. "We started clapping like crazy. In fact, as I was deplaning, I dropped my bag and shook the pilot's hand and thanked him wholeheartedly for the work that he had done. Hats off to the Southwest crew. They did a great job."